Stocking Density: UHDG, MIG, OMG!

In many of the forage and livestock programs, educators promote extending the grazing season as it is less costly than feeding stored forages such as hay. The norm for grazing management on many of our beef cattle operations is an extensive, low input, and hands-off approach. As soon as the grass starts to green up and the cows start to pick at grass, a sigh of relief is expressed by many of us. Some may even do a fist pump while screaming “Yes, no more hay feeding!”
In a handful of research studies, the time spent grazing was approximately 7.5-10.5 hours per day. Realize that cattle do not graze all day long; they spend nearly the same amount of time ruminating or chewing their cud and resting as they do grazing. How we manage the grass presented to cattle can impact the efficiency of grazing. As pasture height is decreased, the number of bites per minute increases to compensate for the lower intake per bite. Ideally, we would want an animal to consume as much per bite as possible to maximize intake and exert less energy grazing.

Managed intensive grazing (MIG), also commonly referred to as rotational grazing, is simply what the name states. The focus is a balance between forage production and animal performance; the objective being to minimize the grazing of new regrowth of the plant while keeping plants vegetative and provide a rest period that allows root reserves to be replenished. Generally, the result is in an improvement in forage production, botanical composition and in some instances animal performance. In several cases the carrying capacity, which is the pounds of animal that can be effectively managed over the entire grazing season or a given length of time, is also increased with managed grazing.

Stocking density is a term that we must understand before we talk about UHDG. Stocking density relates to the number of animals or more often the total pounds on a given amount of land at any point in time. This is different than stocking rate which is the number of animals or pounds per unit of land for a set period of time. These terms can be easily confused. But it is important to understand because with Ultra High Density Grazing (UHDG) or tall grass grazing or mob grazing, whichever term you care to use, the stocking densities reported range from 200,000 lbs per acre to over one million pounds per acre.
A producer with a 100 acre farm considering UHDG would initially look at a stocking density of 500,000 lbs/acre and think that they would need 100,000 steers. They quickly dismiss this as a joke and move on as they know there is absolutely no way the farm could come close to supporting this number of cattle. But they were considering carrying capacity, not stocking density which is what the folks discussing UHDG talk about. Alternatively, if we had 50 steers that weighed 500 lbs and the cattle were moved every 12 hours, the paddock size might be only a tenth of an acre which would allow for a stocking density of 250,000 lb / acre. (50 hd * 500 lb/hd / 0.10 acre =250,000 lb/acre).

Is this even possible? You need to consider that producers with really high stocking densities are moving the cattle several times a day. Additionally, an area may only be grazed 2-3 times a year compared to 5-6 in MIG systems. This allows significant rest for the forages and development of an extensive root system.
Currently, there is limited science-based research investigating UHDG, which makes it difficult for one to make a solid recommendation. Variances in soil types, precipitation received, forage base and species grazed are expected to all have impacts on the outcomes. Many areas that have seen positive responses have been in regions with limited rainfall or less rainfall than what our region receives.
With increasing grain costs, a focus on forage production and grazing management will be a cost effective management decision. Visit with a forage and/or grazing specialist to prioritize what items need to be addressed to implement managed grazing on your farm that will result in the best return on your investment from both short- and long-term perspectives.

OMG that’s it! Have a great grazing season and spend some time this summer evaluating your forage production options to reduce your input costs for your beef operation.